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Diffstat (limited to 'include/X11/Xalloca.h')
| -rw-r--r-- | include/X11/Xalloca.h | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/include/X11/Xalloca.h b/include/X11/Xalloca.h new file mode 100644 index 0000000..1919884 --- /dev/null +++ b/include/X11/Xalloca.h @@ -0,0 +1,121 @@ +/* + +Copyright 1995, 1998 The Open Group + +Permission to use, copy, modify, distribute, and sell this software and its +documentation for any purpose is hereby granted without fee, provided that +the above copyright notice appear in all copies and that both that +copyright notice and this permission notice appear in supporting +documentation. + +The above copyright notice and this permission notice shall be +included in all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR +OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, +ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR +OTHER DEALINGS IN THE SOFTWARE. + +Except as contained in this notice, the name of The Open Group shall +not be used in advertising or otherwise to promote the sale, use or +other dealings in this Software without prior written authorization +from The Open Group. + +*/ +/* + * The purpose of this header is to define the macros ALLOCATE_LOCAL and + * DEALLOCATE_LOCAL appropriately for the platform being compiled on. + * These macros are used to make fast, function-local memory allocations. + * Their characteristics are as follows: + * + * void *ALLOCATE_LOCAL(int size) + * Returns a pointer to size bytes of memory, or NULL if the allocation + * failed. The memory must be freed with DEALLOCATE_LOCAL before the + * function that made the allocation returns. You should not ask for + * large blocks of memory with this function, since on many platforms + * the memory comes from the stack, which may have limited size. + * + * void DEALLOCATE_LOCAL(void *) + * Frees the memory allocated by ALLOCATE_LOCAL. Omission of this + * step may be harmless on some platforms, but will result in + * memory leaks or worse on others. + * + * Before including this file, you should define two macros, + * ALLOCATE_LOCAL_FALLBACK and DEALLOCATE_LOCAL_FALLBACK, that have the + * same characteristics as ALLOCATE_LOCAL and DEALLOCATE_LOCAL. The + * header uses the fallbacks if it doesn't know a "better" way to define + * ALLOCATE_LOCAL and DEALLOCATE_LOCAL. Typical usage would be: + * + * #define ALLOCATE_LOCAL_FALLBACK(_size) malloc(_size) + * #define DEALLOCATE_LOCAL_FALLBACK(_ptr) free(_ptr) + * #include "Xalloca.h" + */ + +#ifndef XALLOCA_H +#define XALLOCA_H 1 + +#ifndef INCLUDE_ALLOCA_H +/* Need to add more here to match Imake *.cf's */ +# if defined(HAVE_ALLOCA_H) || defined(__SUNPRO_C) || defined(__SUNPRO_CC) +# define INCLUDE_ALLOCA_H +# endif +#endif + +#ifdef INCLUDE_ALLOCA_H +# include <alloca.h> +#endif + +#ifndef NO_ALLOCA +/* + * os-dependent definition of local allocation and deallocation + * If you want something other than (DE)ALLOCATE_LOCAL_FALLBACK + * for ALLOCATE/DEALLOCATE_LOCAL then you add that in here. + */ + + +# ifdef __GNUC__ +# ifndef alloca +# define alloca __builtin_alloca +# endif /* !alloca */ +# define ALLOCATE_LOCAL(size) alloca((int)(size)) +# else /* ! __GNUC__ */ + +/* + * warning: old mips alloca (pre 2.10) is unusable, new one is built in + * Test is easy, the new one is named __builtin_alloca and comes + * from alloca.h which #defines alloca. + */ +# if defined(__sun) || defined(alloca) +/* + * Some System V boxes extract alloca.o from /lib/libPW.a; if you + * decide that you don't want to use alloca, you might want to fix it here. + */ +/* alloca might be a macro taking one arg (hi, Sun!), so give it one. */ +# if !defined(__cplusplus) +# define __Xnullarg /* as nothing */ + extern void *alloca(__Xnullarg); +# endif +# define ALLOCATE_LOCAL(size) alloca((int)(size)) +# endif /* who does alloca */ +# endif /* __GNUC__ */ + +#endif /* NO_ALLOCA */ + +#if !defined(ALLOCATE_LOCAL) +# if defined(ALLOCATE_LOCAL_FALLBACK) && defined(DEALLOCATE_LOCAL_FALLBACK) +# define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK(_size) +# define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK(_ptr) +# else /* no fallbacks supplied; error */ +# define ALLOCATE_LOCAL(_size) ALLOCATE_LOCAL_FALLBACK undefined! +# define DEALLOCATE_LOCAL(_ptr) DEALLOCATE_LOCAL_FALLBACK undefined! +# endif /* defined(ALLOCATE_LOCAL_FALLBACK && DEALLOCATE_LOCAL_FALLBACK) */ +#else +# if !defined(DEALLOCATE_LOCAL) +# define DEALLOCATE_LOCAL(_ptr) do {} while(0) +# endif +#endif /* defined(ALLOCATE_LOCAL) */ + +#endif /* XALLOCA_H */ |